.TH std::showbase,std::noshowbase 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::showbase,std::noshowbase \- std::showbase,std::noshowbase

.SH Synopsis
   Defined in header <ios>
   std::ios_base& showbase( std::ios_base& str );   \fB(1)\fP
   std::ios_base& noshowbase( std::ios_base& str ); \fB(2)\fP

   1) Enables the showbase flag in the stream str as if by calling
   str.setf(std::ios_base::showbase).
   2) Disables the showbase flag in the stream str as if by calling
   str.unsetf(std::ios_base::showbase).

   This is an I/O manipulator, it may be called with an expression such as out <<
   std::showbase for any out of type std::basic_ostream or with an expression such as
   in >> std::showbase for any in of type std::basic_istream.

   The showbase flag affects the behavior of integer output (see std::num_put::put),
   monetary input (see std::money_get::get) and monetary output (see
   std::money_put::put).

.SH Parameters

   str - reference to I/O stream

.SH Return value

   str (reference to the stream after manipulation).

.SH Notes

   As specifed in std::num_put::put, the showbase flag in integer output acts like the
   # format specifier in std::printf, which means the numeric base prefix is not added
   when outputting the value zero.

.SH Example


// Run this code

 #include <iomanip>
 #include <iostream>
 #include <locale>
 #include <sstream>

 int main()
 {
     // showbase affects the output of octals and hexadecimals
     std::cout << std::hex
               << "showbase: " << std::showbase << 42 << '\\n'
               << "noshowbase: " << std::noshowbase << 42 << '\\n';

     // and both input and output of monetary values
     std::locale::global(std::locale("en_US.utf8"));
     long double val = 0;
     std::istringstream is("3.14");
     is >> std::showbase >> std::get_money(val);
     std::cout << "With showbase, parsing 3.14 as money gives " << val << '\\n';
     is.seekg(0);
     is >> std::noshowbase >> std::get_money(val);
     std::cout << "Without showbase, parsing 3.14 as money gives " << val << '\\n';
 }

.SH Output:

 showbase: 0x2a
 noshowbase: 2a
 With showbase, parsing 3.14 as money gives 0
 Without showbase, parsing 3.14 as money gives 314

.SH See also

   resetiosflags clears the specified ios_base flags
                 \fI(function)\fP
   setiosflags   sets the specified ios_base flags
                 \fI(function)\fP
